The invention concerns a crankshaft seal flange comprising a support, comprised at least partially of plastic material and comprising at least one dynamic seal that extends about the circumference of an inner wall of a passage of the support, and comprising at least one sensor, provided for detecting the rotary speed and the position of the crankshaft, which is comprised substantially of an electronic component group.
Crankshaft seal flanges serve for sealing crankshafts in motor vehicles. The seal flanges are screwed onto the corresponding crankshaft housing. The crankshaft is extending through the passage of the support of the seal flange and the dynamic seal is resting seal-tightly against its circumference. In order to detect the rotary speed as well as the position of the crankshaft, the seal flange is provided with a sensor which is interacting with a trigger wheel that is fixedly seated on the crankshaft. The sensor is a separate component that is screwed onto the support. In order for the sensor to assume an exact position, a radial guide for the sensor is provided on the support and is located in one lateral face of the seal flange and extends into the inner wall of the support. When the sensor is mounted, between it and the sidewall of the guide a gap remains that is extending from the inner wall of the support in outward direction.
Since the sensor is screwed onto the support, it is complicated to position the sensor in an exact position relative to the seal flange or the support because, when tightening the screw, it cannot be prevented that the position of the sensor, that is affected by tolerances anyway, changes radially, tangentially as well as axially. Also, the sensor connection is sensitive to vibrations and shocks so that the measuring precision can be impaired. For connecting the sensor to the seal flange, connecting elements are required that not only make the manufacture of the seal flange more expensive but also lead to a cumbersome and complex assembly. The screws as well as the centering bushing on the sensor are required as connecting elements. On the seal flange. a threaded centering insert must be provided into which the screw is screwed for fastening the sensor.
Over time, the radially extending gap between the guide wall and the sensor causes deposits to be formed in this area which are undesirable in use of the seal flange. Also, by means of this radial gap, dirt from the exterior can be introduced into the seal flange. The connecting elements cause the sensor area to have a certain size and accordingly require a large installation space. Due to the radial gap, swirls are generated in the area of the sensor when the seal flange is in use so that the measuring precision and the sealing function are impaired.
The invention has the object to configure the crankshaft seal flange of the aforementioned kind in such a way that, while providing a simple and inexpensive manufacture, a reliable measuring action of the sensor as well as a reliable testing of the seal tightness of the seal flange are enabled.